In various fields of art, various surfactants are widely used as washing agents, solubilizers, emulsifiers and dispersing agents. Substances to be solubilized, emulsified or dispersed may include dirt to be washed off, as well as oils and fats, agents and chemical products in the field of pharmaceuticals.
As high-molecular surfactants has been known polyoxyethylene monostearate, polyoxyethylene monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene monolauryl ether, polyvinyl pyrrolidone, carboxymethyl cellulose, hydroxypropyl cellulose, gelatine and gum arabic. However, when such high-molecular surfactants are used as a skin washing agent, these surfactants cannot always give a good effect on skin. Particularly, such surfactants cannot give a moistness feeling on skin.
In the pharmaceutical field, the various high-molecular surfactants are known to be useful as a suspending agent or an emulsifying agent (Japanese Pharmacopoeia, 13th edition, Hirokawa Shoten, Tokyo, 1996).
Further, it is known that albumin, gelatine, starch or agarose, which are surfactants derived from natural organisms, can be used as a drug carrier for improving apparent solubility of a drug (Iyakuhin no Kaihatsu (development of pharmaceuticals), 13th edition, Yakubutsusoutatsuhou (drug derivery), edited by Hitoshi SEZAKI, Torakawa Shoten (1995), p216-331). It is also known that a block copolymer of polyethylene glycol-poly amino acid, a surfactant not derived from natural organisms, can be used as a drug carrier (Japanese Laid-open Patent Application No.1994-107565).
The safety of the above-mentioned surfactants derived from natural organisms is lowered by contamination. The surfactants not derived from natural organisms do not exhibit sufficient solubilizing, emulsifying or dispersing ability depending on the nature of substances to be solubilized, emulsified or dispersed.
It is known that a homopolymer of 2-methacryloyloxyethyl phosphorylcholine and a copolymer of 2-methacryloyloxyethyl phosphorylcholine and hydrophilic and/or hydrophobic monomers exhibit moisture retaining effect and anti-chapping effect on skin, and can be used for cosmetics (Japanese Laid-open Patent Application Nos.93-70321, 94-157269, 94-157270 and 94-157271). However, it is not known that these polymers exhibit solubilizing, emulsifying and dispersing effect.